It was opened for Hillingdon residents' use only last month, but the centre is now available for all following this grand opening.

Mr Johnson, in typically jovial mood, said: "This outstanding accessible sports complex is a real boost for everyone in the area whether you're striving to be the next Mark Spitz or just trying to shift a few pounds and get a bit healthier before the sun arrives.

"The fact that it's open to everyone - young, old, able-bodied and disabled - is something Hillingdon Council should rightly be proud of.

"With this centre, Brunel University down the road and the other leisure facilities being constructed in the area, this part of London will be a nursing ground for athletic talent for years to come."

He bulked at the idea of taking a dip following the ceremony but added: "I can't think of anything nicer than coming somewhere like this on bright Sunday afternoon and having a swim. Sadly, I don't think people would take kindly to seeing me in my shorts."

The only other 50m pool in London, in Crystal Palace, was built in 1964.

Leader of the Council Ray Pudifoot accompanied Mr Johnson on his tour, and emphasised the importance of maintaining the historic character of the centre.

He said: "The council's investment in the complex has ensured we can provide top class facilities for people of ages and abilities.

"With support from the LDA, Sport England and Heritage Lottery Fund, we have taken the opportunity to develop a unique complex that gives people access to excellent, modern leisure facilities, as well as securing the long term future of one our historical assets."